First results from imaging Riomter installed at Indian ...

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... Riomter installed at Indian Antarctic station Maitri, Antarctica. Jayanta K. Behera. 1. , A. K. Sinha. 1. , Anand K. Singh. 2. , Rahul Rawat. 1. , Geeta Vichare. 1.
revised version_changes accepted Click here to download Manuscript: revised version_changes accepted.docx Click here to view linked References 1 2 3 4 5 6 7 8 9 10 11 Jayanta K. Behera1, A. K. Sinha1, Anand K. Singh2, Rahul Rawat 1, Geeta Vichare1, Ajay 12 13 14 Dhar1, B. M. Pathan1, K. U. Nair3,C. Selvaraj3 and P. Elango3 15 16 17 1. Indian Institute of Geomagnetism, New Panvel (W), Navi Mumbai 410 218, India. 18 2. National Centre for Antarctica and Ocean Research, Headland Sada, Vasco-da-Gama, 19 Goa 403 804, India. 20 21 3. Equatorial Geophyscal Research Laboratory, VittalapuramVilakku, Krishnapuram, 22 Maharajanagar, Tirunelveli 627 011, India. 23 24 25 26 27 Abstract: 28 29 Cosmic noise absorption (CNA) measurred by imaging Riometer, is an excellent tool to 30 31 passively study the high latitude D-region ionospheric conditions and dynamics. An imaging 32 33 Riometer has been installed at Indian Antarctic station Maitri (Geographic 70.75 degree S, 11.75 34 35 degree E; corrected geomagnetic 63.11 degree S, 53.59 degree E) in February 2010. This is the 36 37 first paper using the imaging Riometer data from Maitri. Present paper introduces the detail of 38 39 this facility, including its instrumentation, related CNA theory and its applications. Sidereal shift 40 of around 2 hours in the diurnal pattern validates the data obtained from the newly installed 41 42 instrument. Moreover, the strength of cosmic noise signal on quiet days also varies with months. 43 44 This is apparently due to solar ionization of D-region ionosphere causing enhanced electron 45 46 density where collision frequency is already high. The main objective of installing the imaging 47 48 Riometer at Maitri is to study magneotspheric-ionospheric coupling during substorm processes. 49 50 In the current study, we present two typical examples of disturbed time CNA associated with 51 storm-time and non-storm time substorm. Results reveal that CNA is more pronounced during 52 53 storm-time substorm as compared to non-storm time substorm. The level of CNA strongly 54 55 depends upon the strengthening of convectional electric field and the duration of south-ward 56 57 turning of interplanetary magnetic field before the substorm onset. 58 59 60 61 62 1|P ag e 63 64 65

First results from imaging Riomter installed at Indian Antarctic station Maitri, Antarctica